Make BOLT12 CLI more ergonomic

It was unclear how to create a reusable offer, and `bolt12-receive
1000sat` silently used the amount as the description. Take the amount
positionally with an optional -d description, like bolt11-receive, and
document that offers can be paid repeatedly until they expire.

Author: benthecarman

e2e-tests/tests/e2e.rs

@@ -329,7 +329,7 @@ async fn test_cli_bolt12_receive() {
 	// BOLT12 offers need announced channels for blinded reply paths
 	setup_funded_channel(&bitcoind, &server_a, &server_b, 100_000).await;
 
-	let output = run_cli(&server_a, &["bolt12-receive", "test offer"]);
+	let output = run_cli(&server_a, &["bolt12-receive", "-d", "test offer"]);
 	let offer_str = output["offer"].as_str().unwrap();
 	assert!(offer_str.starts_with("lno"), "Expected lno prefix, got: {}", offer_str);
 
@@ -347,7 +347,7 @@ async fn test_cli_decode_offer() {
 	setup_funded_channel(&bitcoind, &server_a, &server_b, 100_000).await;
 
 	// Create a BOLT12 offer with known parameters
-	let output = run_cli(&server_a, &["bolt12-receive", "decode offer test"]);
+	let output = run_cli(&server_a, &["bolt12-receive", "-d", "decode offer test"]);
 	let offer_str = output["offer"].as_str().unwrap();
 
 	// Decode it
@@ -378,21 +378,21 @@ async fn test_cli_decode_offer() {
 	assert!(decoded.get("amount").is_none() || decoded["amount"].is_null());
 
 	// Test a fixed-amount offer
-	let output_fixed = run_cli(&server_a, &["bolt12-receive", "fixed amount", "50000sat"]);
+	let output_fixed = run_cli(&server_a, &["bolt12-receive", "50000sat", "-d", "fixed amount"]);
 	let decoded_fixed =
 		run_cli(&server_a, &["decode-offer", output_fixed["offer"].as_str().unwrap()]);
 	assert_eq!(decoded_fixed["amount"]["amount"]["bitcoin_amount_msats"], 50_000_000);
 
 	// Test that ANSI escape sequences cannot reach the terminal via CLI output.
 	let desc_with_ansi = "offer\x1b[31m RED \x1b[0m";
-	let output_ansi = run_cli(&server_a, &["bolt12-receive", desc_with_ansi]);
+	let output_ansi = run_cli(&server_a, &["bolt12-receive", "-d", desc_with_ansi]);
 	let raw_decoded =
 		run_cli_raw(&server_a, &["decode-offer", output_ansi["offer"].as_str().unwrap()]);
 	assert!(!raw_decoded.contains('\x1b'), "Raw CLI output must not contain ANSI escape bytes");
 
 	// Test that Unicode bidi override characters in the description are escaped
 	let desc_with_bidi = "offer\u{202E}evil";
-	let output_bidi = run_cli(&server_a, &["bolt12-receive", desc_with_bidi]);
+	let output_bidi = run_cli(&server_a, &["bolt12-receive", "-d", desc_with_bidi]);
 	let raw_bidi =
 		run_cli_raw(&server_a, &["decode-offer", output_bidi["offer"].as_str().unwrap()]);
 	// LDK exposes offer descriptions through PrintableString, which may replace

ldk-server-cli/src/main.rs

@@ -339,17 +339,33 @@ enum Commands {
 		)]
 		max_channel_saturation_power_of_half: Option<u32>,
 	},
-	#[command(about = "Return a BOLT12 offer for receiving payments")]
+	#[command(
+		about = "Create a reusable BOLT12 offer for receiving payments",
+		long_about = "Create a reusable BOLT12 offer for receiving payments.\n\n\
+			A BOLT12 offer can be paid any number of times, by any number of payers, until it \
+			expires. Without --expiry-secs the offer never expires, so it can be shared publicly \
+			(e.g. for donations or a static payment code). Omit the amount to let each payer \
+			choose how much to send."
+	)]
 	Bolt12Receive {
-		#[arg(help = "Description to attach along with the offer")]
-		description: String,
 		#[arg(
-			help = "Amount to request, e.g. 50sat or 50000msat. If unset, a variable-amount offer is returned"
+			help = "Amount to request per item, e.g. 50sat or 50000msat. If unset, a variable-amount offer is returned"
 		)]
 		amount: Option<Amount>,
-		#[arg(long, help = "Offer expiry time in seconds")]
+		#[arg(short, long, help = "Description to attach along with the offer")]
+		description: Option<String>,
+		#[arg(
+			short,
+			long,
+			help = "Offer expiry time in seconds. If unset, the offer never expires"
+		)]
 		expiry_secs: Option<u32>,
-		#[arg(long, help = "Number of items requested. Can only be set for fixed-amount offers")]
+		#[arg(
+			short,
+			long,
+			requires = "amount",
+			help = "Maximum number of items a payer may buy per payment. Only for fixed-amount offers"
+		)]
 		quantity: Option<u64>,
 	},
 	#[command(about = "Send a payment for a BOLT12 offer")]
@@ -1112,12 +1128,12 @@ async fn main() {
 					.await,
 			);
 		},
-		Commands::Bolt12Receive { description, amount, expiry_secs, quantity } => {
+		Commands::Bolt12Receive { amount, description, expiry_secs, quantity } => {
 			let amount_msat = amount.map(|a| a.to_msat());
 			handle_response_result::<_, Bolt12ReceiveResponse>(
 				client
 					.bolt12_receive(Bolt12ReceiveRequest {
-						description,
+						description: description.unwrap_or_default(),
 						amount_msat,
 						expiry_secs,
 						quantity,

ldk-server-grpc/src/api.rs

@@ -537,6 +537,8 @@ pub struct Bolt11SendUnderpayingResponse {
 }
 /// Returns a BOLT12 offer for the given amount, if specified.
 ///
+/// The offer is reusable: it can be paid any number of times until it expires.
+///
 /// See more:
 /// - <https://docs.rs/ldk-node/latest/ldk_node/payment/struct.Bolt12Payment.html#method.receive>
 /// - <https://docs.rs/ldk-node/latest/ldk_node/payment/struct.Bolt12Payment.html#method.receive_variable_amount>
@@ -550,13 +552,15 @@ pub struct Bolt12ReceiveRequest {
 	/// Will be set in the description field of the encoded offer.
 	#[prost(string, tag = "1")]
 	pub description: ::prost::alloc::string::String,
-	/// The amount in millisatoshi to send. If unset, a "zero-amount" or variable-amount offer is returned.
+	/// The amount in millisatoshi to request per item. If unset, a "zero-amount" or variable-amount
+	/// offer is returned.
 	#[prost(uint64, optional, tag = "2")]
 	pub amount_msat: ::core::option::Option<u64>,
-	/// Offer expiry time in seconds.
+	/// Offer expiry time in seconds. If unset, the offer never expires.
 	#[prost(uint32, optional, tag = "3")]
 	pub expiry_secs: ::core::option::Option<u32>,
-	/// If set, it represents the number of items requested, can only be set for fixed-amount offers.
+	/// If set, the maximum number of items a payer may request in a single payment. This does not
+	/// limit how many times the offer can be paid. Can only be set for fixed-amount offers.
 	#[prost(uint64, optional, tag = "4")]
 	pub quantity: ::core::option::Option<u64>,
 }

ldk-server-grpc/src/proto/api.proto

@@ -409,6 +409,8 @@ message Bolt11SendUnderpayingResponse {
 
 // Returns a BOLT12 offer for the given amount, if specified.
 //
+// The offer is reusable: it can be paid any number of times until it expires.
+//
 // See more:
 // - https://docs.rs/ldk-node/latest/ldk_node/payment/struct.Bolt12Payment.html#method.receive
 // - https://docs.rs/ldk-node/latest/ldk_node/payment/struct.Bolt12Payment.html#method.receive_variable_amount
@@ -418,13 +420,15 @@ message Bolt12ReceiveRequest {
   // Will be set in the description field of the encoded offer.
   string description = 1;
 
-  // The amount in millisatoshi to send. If unset, a "zero-amount" or variable-amount offer is returned.
+  // The amount in millisatoshi to request per item. If unset, a "zero-amount" or variable-amount
+  // offer is returned.
   optional uint64 amount_msat = 2;
 
-  // Offer expiry time in seconds.
+  // Offer expiry time in seconds. If unset, the offer never expires.
   optional uint32 expiry_secs = 3;
 
-  // If set, it represents the number of items requested, can only be set for fixed-amount offers.
+  // If set, the maximum number of items a payer may request in a single payment. This does not
+  // limit how many times the offer can be paid. Can only be set for fixed-amount offers.
   optional uint64 quantity = 4;
 }
 

ldk-server-mcp/src/tools/mod.rs

@@ -193,7 +193,7 @@ pub fn build_tool_registry() -> ToolRegistry {
 		),
 		tool_spec(
 			"bolt12_receive",
-			"Create a BOLT12 offer for receiving Lightning payments",
+			"Create a reusable BOLT12 offer for receiving Lightning payments",
 			schema::bolt12_receive_schema,
 			|client, args| Box::pin(handlers::handle_bolt12_receive(client, args)),
 		),

ldk-server-mcp/src/tools/schema.rs

@@ -430,18 +430,17 @@ pub fn bolt12_receive_schema() -> Value {
 			},
 			"amount_msat": {
 				"type": "integer",
-				"description": "Amount in millisatoshis. If unset, a variable-amount offer is returned"
+				"description": "Amount in millisatoshis to request per item. If unset, a variable-amount offer is returned"
 			},
 			"expiry_secs": {
 				"type": "integer",
-				"description": "Offer expiry time in seconds"
+				"description": "Offer expiry time in seconds. If unset, the offer never expires"
 			},
 			"quantity": {
 				"type": "integer",
-				"description": "Number of items requested. Can only be set for fixed-amount offers"
+				"description": "Maximum number of items a payer may request in a single payment. Does not limit how many times the offer can be paid. Can only be set for fixed-amount offers"
 			}
-		},
-		"required": ["description"]
+		}
 	})
 }